1. Field of the Invention
This disclosure relates to a liquid discharge head configured to discharge liquid.
2. Description of the Related Art
In the related art, an inkjet recording head (hereinafter, referred to also as a recording head) as a liquid discharge head is configured to introduce inks in a plurality of colors introduced from ink tanks or the like into an ink discharge unit via supply channels formed in an interior of the recording head.
Japanese Patent Laid-Open No. 2002-019146 discloses a recording head configured to introduce ink via a joint seal member (resilient member) formed of a resilient material provided between a tank holder unit (hereinafter, referred to also as a holder unit) and an ink discharge unit (hereinafter, referred to also as a discharge unit). FIG. 1 is an exploded perspective view of a recording head of the related art. FIGS. 2A and 2B are schematic drawings illustrating a cross section of part of the recording head. FIG. 2A illustrates a state in which assembly of the recording head is completed.
A holder unit H10 is a member to which an ink tank is mounted, and is provided with an ink inlet portion to be connected to the ink tank via a filter. The holder unit H10 includes an ink supply channel H11 formed in an interior thereof, and one end of the ink supply channel H11 has a configuration being formed in an interior of a projection H12 projecting toward a discharge unit H20.
The discharge unit H20 is a member configured to discharge ink, and the discharge unit H20 includes an ink supply channel H23 formed corresponding to the ink supply channel H11 of the holder unit H10.
A joint seal member H30 is arranged between the holder unit H10 and the discharge unit H20, and the joint seal member H30 is provided with a through hole H31 for connecting the ink supply channel H11 and the ink supply channel H23 formed therethrough.
Lip portions H32 for enhancing hermeticity when being pressed by the holder unit H10 and the discharge unit H20 are provided around openings on both ends of the through hole H31 of the joint seal member H30. The joint seal member H30 being interposed between the holder unit H10 and the discharge unit H20 and being pressed thereby secures a sealing property between the holder unit H10 and the discharge unit H20. With the provision of the joint seal member H30, a connection between the holder unit H10 and the discharge unit H20 is achieved without using an adhesive agent, and hence selection of the adhesive agent considering anti-ink properties is not necessary and, in addition, an assembly step of the recording head may be simplified.
In a process of manufacturing the recording head includes a step of inspecting a discharging performance of the recording head by discharging ink before shipping. In a state in which the ink in the inspection step remains in the supply channel, the ink is cured before a user receives the recording head, and hence the performance of the recording head may disadvantageously be impaired. Accordingly, a step of removing the ink in the supply channel is performed after the inspection step.
In order to remove the ink, an interior of the supply channel is cleaned by a washing liquid, and then compressed hot air is fed into the supply channel from the ink inlet portion for drying up the washing liquid. FIG. 2B is a schematic drawing of part of the cross section of the recording head, and illustrates a state in which compressed air is fed from the ink inlet portion for washing the interior of the supply channel and drying up the washing liquid.
Here, if the interior of the supply channel assumes a compressed state when washing and drying up the interior of the supply channel, the joint seal member H30 may be deformed in a direction indicated by an arrow K, and may not restore its original shape even after air feed is stopped. In this case, the lip portions H32 may be displaced and cannot maintain the hermeticity and, consequently, washing or drying may not be performed sufficiently. In such a case, a space may be formed by depression inward of the supply channel due to a deformation of the lip portions H32 and the washing liquid may remain in the space. The remaining washing liquid may be increased in viscosity and anchored, and consequently impair a discharge of the ink as a foreign substance during distribution (during a period until the user receives the recording head). In addition, when the degree of deformation is significant, the hermeticity in the ink supply channel cannot be maintained, and hence a leakage of ink may occur. In contrast, if an air pressure at the time of drying is lowered, a period required for drying the interior of the supply channel is increased, and hence lowering of productivity of the recording head results.